Field
Embodiments of the present disclosure generally relate to methods for forming a film on a semiconductor surface.
Description of the Related Art
Semiconductor device geometries have dramatically decreased in size since their introduction several decades ago. Modern semiconductor fabrication equipment routinely produces devices with 45 nm, 32 nm, and 28 nm feature sizes, and new equipment is being developed and implemented to make devices with even smaller geometries. The decreasing device sizes result in structural features having decreased aspect ratios, or decreased width relative to height of features within the formed device. As features narrow in width, gap-filling and patterning become more challenging.
Filling features with lower aspect ratios presents challenges because of the risk of voids. Voids occur when deposited material adheres not only to the bottom of features but also to sidewalls, growing across the feature before it is completely filled. Such voids result in decreased reliability of integrated circuits.
Selective deposition of silicon oxide film on other dielectric films is desirable for bottom-up gap-fill and patterning applications. One effective method for selective deposition of silicon oxide film comprises flowing tetraethyl orthosilicate (TEOS) and ozone over a substrate at sub-atmospheric pressure. Although silicon oxide film will grow on a silicon surface using this method, it will also grow on silicon nitride or thermal silicon oxide surfaces.
Therefore, there is a need for improved methods of selectively filling patterned a semiconductor structures that are formed through silicon nitride and silicon oxide layers.